Firstly, the proposer role is already decentralized in a sense since both proposing and challenging L2 state roots are permissionless with BoLD (i.e. anyone is allowed to fulfill the role). Secondly, trustless bonding pools will be available for individuals to use to pool funds together to fulfill this role with no minimum bond requirement. Lastly, as mentioned in the BoLD AIP, the documentation about BoLD, and the BoLD whitepaper, there is no technical need for more than 1 active, honest party advancing a BoLD-enabled chain at any given point in time. Since what the proposer does is fully deterministic so that there’s no real advantage to being the proposer in terms of power over the system, what’s the concern that you’re interested in resolving via decentralizing the proposer?